1. Field of Invention
The present invention generally relates to thermal insulating supporting devices for piping, and more particularly to such devices which are used for the secure thermal insulated support of piping for transporting various types of cryogenic-temperature fluids.
2. Description of the Related Art
To install piping for transporting cryogenic-temperature fluids such as LNG (liquified natural gas) or LPG (liquefied petroleum gas) in specified locations during the construction of various types of plants, supporting devices having an appropriate thermal insulating performance are required in order to achieve secure support of the weight of the piping and the fluid contained in the piping.
As shown in FIG. 7, a conventional piping supporting device A is so assembled that an upper plate A1 and an under plate A2 are connected to each other by anchor bolts A4 with various types of thermal insulated members A3a through A3g being clamped between the upper plate A1 and under plate A2. Piping P is installed in a bracket A5 which is disposed on the upper plate A1 therefor has been provided as a supporting device which satisfies the above mentioned conditions.
However, in the supporting device A described above, although the weight of the piping P and the fluid contained in the piping can be securely supported, since the upper plate A1 and under plate A2 are connected by the anchor bolts A4, heat in the piping P is transferred via the bracket A5, upper plate A1 and anchor bolts A4 so that a large heat loss is experienced.
There is another conventional prior art supporting device which has an appropriate thermal insulating performance and which is capable of securely supporting the weight of the piping and the fluid contained in the piping. In this supporting device, the outer circumference of the piping is covered by a thermal insulating material, and a piping support is formed from a molded urethane block in accordance with the thickness of the thermal insulating material and the external diameter of the piping, with the piping being fastened in place in a specified position via the piping support.
Specifically, as shown in FIG. 8, a supporting device B is so assembled that urethane blocks B1a, B1b, B1c are mounted on the outer circumference of the piping P as thermal insulating members. The urethane blocks B1a, B1b, B1c are covered by a pair of pipe clamps B2a, B2b, and the piping P is supported in a specified position with a shoe B3 which is fastened to the pipe clamp B2a. This supporting device B has effective thermal insulating properties as a result of the provision of the urethane blocks B1a through B1c.
However, the respective urethane blocks B1a through B1c are specially manufactured in accordance with the size (external diameter) of the piping P. Accordingly, not only are the costs involved in design and manufacture at the factory extremely high, but the personnel costs involved in the control of the respective unit parts from the design stage to the installation stage are also considerable.
Furthermore, since piping designs are frequently altered according to on-site conditions, there is not only a further increase in cost due to accompanying design alterations in the piping support, but also a significant increase in various other costs, such as the transportation cost involved in the transportation of urgent additional orders of piping supports or new piping supports to the site.
Moreover, in cases where there are unavoidable design changes in piping and piping supports at piping construction sites, it is often necessary to communicate with the factory in order to order new piping supports, and to wait for the new piping supports to be delivered to the construction site following design and manufacture at the factory. Accordingly, there is a danger that on-site construction schedules may be greatly delayed, thus causing disruptions in the overall scheduling of plant construction projects.